In the past, several different methods and techniques have been used to cut glass sheets. The most widely used method is mechanical scoring using a wheel made of a hard material and breaking the glass along the score line. The mechanical scribing and breaking process generates debris that collects on the glass surface and requires thorough cleaning. Therefore, glass technology areas that require high glass quality, such as the LCD industry, cannot reliably use mechanical scribing techniques to form glass sheets.
Other widely used methods include the use of lasers to score and/or separate glass sheets. In one technique, a laser beam is used to score the glass; the glass is then separated by mechanical separation techniques. When the laser beam is moved across the glass sheet, it creates a temperature gradient on the surface of the glass sheet, which is enhanced by a coolant (such as a gas or liquid) that follows the laser beam at some distance. Specifically the heating of the glass sheet by the laser and the rapid cooling of the glass sheet by the coolant creates tensile stresses in the glass sheet. The tensile stresses create a crack (or score vent) in the glass surface. In this manner, a score line is created along the glass sheet. The glass sheet can then be separated into two smaller sheets by separating the glass sheet along the score line. Yet another technique uses a first laser beam to score the glass. A second laser beam of a different configuration is used to accomplish laser separation.
Conventional techniques generally employ an elongated laser beam to provide enhanced scoring speed. Due to the elongation of the laser beam that is needed to achieve higher scoring speeds, these techniques are limited to linear scoring trajectories.
Thus, there is a need in the art for systems and methods to cut glass sheets along curved trajectories.